(1) Field of the Invention
The present invention relates to a vortex blower.
(2) Description of the Related Art
A vortex blower has the feature that its pressure coefficient which is a dimensionless value indicating a work load per unit impeller diameter is high in comparison with that of a centrifugal blower, and has been heretofore widely used as a blower having a relatively small capacity. There has been presented an increased demand of miniaturization, high-pressurization, noise reduction and the like for the vortex blower, and accordingly, various proposals have been made for improving the configuration of a partition wall between a suction port and a discharge port, provided on a static passage in order to achieve the above-mentioned demand.
The configuration of the partition wall of the conventional vortex blower has been variously studied in order to enhance the aerodynamic performance and to reduce noise. For example, as disclosed in JP-A-51-27111 or JP-B2-2680136, a vortex blower which reduces noise in view of a correlation between the configuration of blades of an impeller and the configuration of the partition wall.
JP-A-51-27111 discloses a vortex blower having the configuration which aims at reducing noise in the case that the shape of blades of an impeller is linear in the radial direction thereof. That is, the partition wall has a discharge side shape with which a stream is finally shut off at the flow center at which flow variation is minimum. Further, the partition wall have the shape that it gradually partitions a stream, from the inner peripheral side, rather than finally partitioning the stream at a point where the flowing speed on the outer peripheral side is maximum, so as to aim at reducing noise.
The above-mentioned JP-B2-2680136 proposes a vortex blower including an impeller with blades which have a three-dimensionally curved so as to increase the pressure coefficient in order to reduce noise. In this vortex blower, the partition wall is provided with guides which overlap with a suction port and a discharge port on a static passage as viewed in front of the vortex blower, the guide on the suction side having the shape that its front end cuts the blade from the outer peripheral side of the impeller, but is opened to the static flow passage from the inner peripheral side while the guide on the discharge side has the shape that it partitions the blades from the inner peripheral side of the impeller, and as a result, the stream matches the velocity distribution of a vortex-like stream generated between the impeller and the casing, thereby it is possible to reduce noise.